[PATCH 5/8] gpio: 74x164: Add output pin support

[Eric Bénard]

Hi,

Le Wed, 5 Sep 2012 12:09:06 +0200,
Thomas Petazzoni <thomas.petazzoni at free-electrons.com> a écrit :
> I don't think the /OE pin can be used as a chip select, because when it
> is high, the state of the output pins is not maintained to their
> previous state: the pins are turned into the high impedance state. If
> used as a chip select, it would mean that the value of the output pins
> transition from their old state to high impedance at the beginning of
> the transfer, and then from the high impedance to their new state at
> the end of the transfer.

OK that's exactly what I was thinking to ;-)

> And of course, this signal is inverted compared to a normal chip select.

polarity of the chip select can vary (mc13xxx-spi has an active high CS
for example).

Eric